This invention relates to the control of plural electrical signals. More particularly, this invention relates to a microprocessor-controlled control station for the delivery and monitoring of plural electrical signals to a utilization device.
Electrical apparatus rarely is operable on the available electrical power in the form in which it is received from the source, be that a generator, power supply or the common 110V AC wall outlet. Consequently, electrical controls are provided to adapt the available electrical supply to the form, i.e. the voltages, currents and power levels, required by the apparatus. Conventionally, transformers, with or without voltage and/or current converters, perform this function. But in addition to the function of such conversion, protection requirements for personnel and equipment must be satisfied. In addition, programmable control over the output voltages may also be desired.
One field in which this need exists is that of model electric trains. Many of these are sold as toys to be used by children and so the protection of personnel must be a principal concern. Others are sold to model railroad enthusiasts who desire realistic operation and so the programmable control feature is important to these persons.
Generally, operation of model electric trains is facilitated by an electric transformer which is operatively linked to a model train track circuit of a model train layout. The transformer provides an electric power signal to the model train track which is coupled to an internal motor of the electric train engine, typically by way of metallic wheels or contacts electrically contacting the track. In O-gauge systems, the voltage required to drive the engine is an AC voltage, unlike typical HO-gauge systems which employ a DC voltage.
Model train enthusiasts, especially those preferring the O-gauge scale, have long had available the line of products manufactured by Lionel Trains Inc., now of New Baltimore, Mich. Such model train products were introduced in the United States early in the 20th century and experienced their greatest popularity after to World War II. The early popularity of O-gauge electric train products coincided with the widespread use of electrical devices which occurred after World War II and resulted in a de-facto electrical standard in the O-gauge model train industry based on the operation of that type of transformer and motorized train engine. As such, O-gauge train engines and accessories such as those currently manufactured by Mike""s Train House (MTH and Rail King brand trains) and others are designed to operate on electrical signals consistent with the type standardized by the old standard O-gauge transformer stations.
Standard O-gauge electrical train operation is characterized by an AC track signal, wherein the AC signal is switchably offset by a DC signal used to enable various train accessories such as the horn/whistle function. The AC track signal energizes the electric motor of the train engine, with the DC offset enabling a train engine relay unit to activate the appropriate bell or whistle feature. Additionally, certain standard O-gauge type transformers include fixed AC voltage supply terminals for operating lights and additional accessories.
This basic electrical standard, namely the AC track signal voltage and DC control offset popularized by the standard O-gauge transformer, has been adhered to by current manufacturers to ensure compatibility of their products and accessories with those already in use. The standardization of this power arrangement ensures the continued compatibility of vintage train engines with new engines and other model train technologies.
Presently, hobbyists either recondition vintage standard O-gauge transformers or rely on new compatible transformers to power their O-gauge layouts. Yet, reconditioned transformers on their own cannot readily take advantage of modern train sound effects and control technologies and they lack the capabilities necessary to intelligently control and monitor system accessories and power consumption. Moreover, new transformers are incapable of delivering the power associated with vintage standard O-gauge transformers because they must comply with more stringent modern electrical safety standards, such as those promulgated by Underwriters Laboratory (UL).
Accordingly, there is a need for an electric control station that provides power supply limiting and data processing for intelligently monitoring and controlling power consumption. In particular, a plural output electric control station is needed that manages the power capacity of a plurality of outputs to ensure that a maximum power rating is not exceeded by a single output or by any combination of outputs. Additionally, a station is needed to provide an adaptive control for integrating and programming new train accessory technologies.
Accordingly, electrical control apparatus according to the present invention comprises at least two outputs at which respective first and second electrical signals are to be produced. A controllable first electrical source is coupled to at least one of the outputs for supplying the first electrical signals, wherein the controllable electrical source is responsive to a first control signal for controlling the magnitude of the first electrical signal. A second electrical source is coupled to the other of the outputs for supplying said second electrical signal. A sensing element is coupled to receive the first electrical signal and to generate a sensed electrical parameter representative of the magnitude of said first electrical signal. A processor is responsive to the sensed electrical parameter for generating the first control signal.
According to another aspect according to the present invention, an electric train control station comprises an input connection adapted to receive electrical power from a source of electrical power and an output connection adapted to supply a controlled electrical signal for a track circuit. A controllable drive circuit is coupled between the input connection and the output connection for generating the controlled electrical signal in response to a first control signal. An input device generates a command signal in response to an operator action and a data processor includes a memory device for storing an instruction set. The data processor executes the instruction set and is coupled to the input device and to the controllable drive circuit to generate the first control signal in response to the command signal and in accordance with the instruction set.
In a further aspect according to the present invention, a method of detecting an interconnection of at least two outputs of a plural output electrical control station, wherein at least one of the outputs is controllable in response to a control value, comprises the steps of: measuring a reference measured value of the voltage at at least one of the outputs thereof; changing the control value of the controllable output in a manner expected to produce a predetermined change of the voltage thereof; calculating from the reference value and the predetermined change an expected value of a second measured value of the voltage at the controllable output; measuring at the at least one of the outputs after the changing the control value of the controllable output the second measured value of the voltage thereof; comparing the second measured value to the calculated expected value; and detecting an interconnection when the second measured value differs from the calculated expected value by more than a predetermined amount.